BIG PHYSICS, BIG QUESTIONS –

#Rosettawatch: homing in on Philae’s resting spot

# Rosettawatch

TWO weeks. It has been two weeks since you landed and I still can’t find you, Philae. I know it’s not my fault you bounced, but I feel responsible. I’m trying to locate you – and I’m getting closer.

Using CONSERT, a radar instrument that links you to me – Rosetta, your mothership – I’ve narrowed down potential landing spots to a 350- by 30-metre strip on comet 67P’s head. My human operators at the European Space Agency are now searching images to see if they can spot you.

As for your drill, it was one of the last instruments to be activated before you switched off. Mission managers know the drill operated as expected, but because you were sitting at an angle, they don’t know whether it delivered a sample to the COSAC instrument. This was designed to study molecules from the comet by heating material and measuring the resulting gas.

“I would have loved to see a clear signal from a clear sample,” says COSAC lead Fred Goesmann. “My pessimistic view is we’ll never know.”

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No more data is expected from you any time soon, and now I am ramping up my scientific mission. I’m back in a higher orbit, 30 kilometres above the comet, but I will dip to 20 kilometres on 3 December for 10 days to gather data on the increasing dust and gas spewing from 67P as it nears the sun. I’ll continue looking for you, Philae.

This article appeared in print under the headline “Where are you, Philae?”